Pressure release mechanism

ABSTRACT

An aerosol container is provided with a safety venting system whereby the product and propellant may be vented from the container when an increase in internal pressure threatens to blow an end off the container. The venting system comprises a plurality of vents formed in the body flange area which are buried in the double seam which joins the container body and end closure. When the internal pressure of the container increases sufficiently, the end closure will buckle outwardly exposing the vents and thereby permitting the contents of the container to safely escape.

United States Patent Pelton Oct. 14, 1975 PRESSURE RELEASE NIECHANISMPrimary ExaminerRobert B. Reeves 75 Inventor: Peter G. Pelton, CarolStream, Ill. P as Attorney, Agent, or Flrm.lohn J. Kowallk; Joseph E.[73] Assignee: Continental Can Company, Inc., K rwi William A. DittmanflNew York, N.Y. v 22 Filed: Aug. 16, 1974 [57] ABSTRACT I An aerosolcontainer is provided with a safety venting [211 498012 system wherebythe product and propellant may be vented from the container when anincrease in inter [52] US. Cl. 222/396 nal pressure threatens to blow anend off the con- [51] Int. Cl. B651) 83/14 tainer. The venting systemcomprises a plurality of [58] Field of Search 222/396, 397, 541; 220/67,vents formed in the body flange area which are buried 220/207; 137/525in the double seam which joins the container body and end closure. Whenthe internal pressure of the con- [56] References Cited tainer increasessufficiently, the end closure will UNITED STATES PATENTS buckleoutwardly exposing the vents and thereby per- 3,786.967 1 1974 Giocomoet al. 222 397 m'ttmg the contents of the Contamer to Safely escape 11Claims, 4 Drawing Figures US. Patent Oct. 14, 1975 22 r 28/ 23FJ24 27PRESSURE RELEASE MECHANISM SUMMARY OF THE INVENTION The presentinvention relates generally to a metal or plastic aerosol containerhaving a pressure relief system whereby the internal contents of thecontainer may be vented therefrom when the internal pressure rises to alevel sufficient to threaten blowing an end off the container. Moreparticularly, this invention relates to a two or three piece metal orplastic aerosol container having a simple venting system to prevent theexplosion of a filled container when the internal pressure risesconsiderably, as may occur during excessive heating of the container.

For many years pressurized aerosol containers have been marketed to thegeneral public. These container usually comprise a three-piece metalcontainer having therein a product to be dispensed; together with apropellant which provides the internal pressure necessary to dispensethe product through a valve mounted on the container top.

However, due to the fact that the container is pressurized, problemshave been encountered when the internal pressure of the container risesrapidly above the design pressure. In some instances this rapid increasein internal pressure, resulting from excessive heating, due to improperstorage or use, has caused the container to explode.

It is, therefore, one of the important objects of the present inventionto provide an improved pressure release mechanism for aerosolcontainers.

It is a further object to provide an improved pressure release mechanismwhich will function regardless of the container orientation.

It is another object to provide an improved pressure release mechanismwhich may be produced with a reasonably wide degree of manufacturinglatitude.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view ofan aerosol container constructed in accordance with this invention,illustrating a plurality of vents formed in portions of the end unitdefining a part of the double seam structure.

FIG. 2 is a fragmentary perspective view of an aerosol container bodyprior to assembly, illustrating vents formed in the body flange.

FIG. 3 is an enlarged fragmentary sectional view taken generally alongline 11 of FIG. 1, illustrating a vent formed in the body flange.

FIG. 4 is a fragmentary sectional view similar to FIG. 3 in which theend unit has buckled outward, illustrating the manner in which the ventsare exposed by the rotation of the chuck wall, thereby allowing escapeof the container contents.

DESCRIPTION OF THE PREFERRED EMBODIMENT In keeping with the presentinvention there is provided a conventional two or three-piece aerosolcontainer inside of which is housed a pressurized product (not shown).The container 10 includes a typical dispensing button and/or nozzle 11which is united to a conventional dispensing valve (not shown) such thatupon depression of the nozzle 11 or angulating the same in non-parallelrelationship to the container axis the product within the container 10is dispensed through the valve and nozzle 11 to atmosphere.

Most aerosol containers 10 include an end unit 12 having a domed portion13 which is crimped at 14 to a conventional valved cup 15. Suchconventional end units 12 further include a chuck wall radius 16 whichjoins the central domed portion 13 at a chuck wall 17. The chuck wall 17in turn merges with a seaming panel 18 through a seaming wall radius 21which in turn in joined to a seaming wall 22 merging with an end hookradius 23 which in turn merges with an end hook 24.

The container body 25 of the aerosol container 10 includes a body wall26 merging with a body hook radius 27 which in turn merges with a bodyhook 28. The body hook 28 is sandwiched and crimped or clamped betweenthe body wall 26, and the seaming wall 22. A sealing compound 29 may beemployed to insure the integrity of this crimped seal.

In keeping with this invention, it has been found that the outerperiphery of the seaming panel 18 of the end unit 12 experiences maximumexpansion and eventually dome failure as the dome 13 is forced axiallyupwardly and outwardly under the influence of excessive internalpressure in the manner illustrated in FIG. 4. Without some type ofpressure relief mechanism, the container 10 would explode, fractureand/or otherwise disintegrate. However, in accordance with the presentinvention such undesired occurance is precluded by the provision of aplurality of vents 30 in the body hook radius 27, said vents 30 beingequally spaced about the periphery of said container body 25. Spacing ofvents at 30 intervals is preferred although other spacing is alsoeffective. Experience indicates that vents should not be placed withinone-half inch of the body wall side seam and should not extend more than0.09 inches inward from the flange periphery.

As internal pressure develops beyond a predetermined design maximum theend unit 12 begins to deflect axially upwardly and outwardly toward theeventual position shown in FIG. 4, thereby uncovering the vents 30. Anysealing compound 29 which may be blocking the vents 30 is forced out ofthe way allowing the high pressure gasses to exit between the body wall26 and the end hook 24. In this manner undesired explosion is precludedand safe and unabrupt venting is achieved with the escaping gasses andother container contents being channeled in streams substantiallyparallel to the axis of the container.

It is understood that the venting ports 30 are made in the body flangearea 28a such that they will be buried in the double seam. Actually,they are covered by the seaming panel 18 of the end unit 12. During anoverpressure condition, the end unit will buckle outward with theseaming panel 18 rotating about This highly reliable mechanicalphenomenon then becomes the opening action essentially it is a poppervalve. With a large enough hole, the compound 29 remaining is forced outof the way, allowing the high pressure gasses or product to exit betweenthe body wall 26 and the end hook 24.

The implication here in that a loose double seam is essential. Actuallythe double seam tightness should be normal. Then during the buckling thedouble seam tends to loosen. This is a result of the outward forcesdeveloped kinematically as the deep counter-sink is lifted, thus forcingthe seaming wall radius 21, and the remainder of the end hook 24outward.

This developed double seam looseness is usually adequate for venting,yet is such that a heavy jetting and subsequent rocketing effect isprevented. The discharge is actually a series of fine streams or spraysand rather well dispersed.

Should a situation develop such that the rate of pressure depletion thruventing is less than the rate of pressure buildup, then the venting ratewill actually be increased. As the pressure on the end unit 12increases, there is a pronounced tendency of the double seam to unfold.As this tendency develops, the effect is to move the end hook 24 outaway from the body 25 thus further opening the vents 30 as an outerpoppet valve.

Experience thus far indicates that double seam integrity is maintainedso that a burst does not occur.

For 3-piece cans this application is possible on either end, preferablythe top end. It can also function for 2- piece.

While preferred forms and arrangement of parts have been shown inillustrating the invention, it is to be clearly understood that variouschanges in details and arrangement of parts may be made departing fromthe scope and spirit of this disclosure.

1 claim:

1. Safety venting means for a double seam structure of the type securingan end unit to a flanged container body, said venting means comprisingopenings buried in said double seam, said openings being uncoverableupon the deflection of said end unit consequent to internaloverpressurization of the container.

2. Safety venting means for a double seam structure of the type securingan end unit to a flanged container body, said venting means comprising aplurality of openings in the body of the container, said openings beingburied in said double seam and being uncoverable upon the deflection ofsaid end unit consequent to internal overpressurization of thecontainer.

3. The invention according to claim 1 wherein said body comprises aradially outwardly directed flange and said openings disposed at thejuncture of said flange and said body and being folded over into saidseam.

4. Safety venting means for a double seam structure of the type securingan end unit to a flanged container body, wherein said body has a flangeat said seam and said venting means comprises at least one opening insaid flange; said opening being buried in said double seam and beinguncoverable upon the deflection of said end unit consequent to internaloverpressurization of the container.

5. The invention according to claim 1 wherein said end unit comprises acentral domed portion and a peripheral relatively rigid portionincluding a seaming panel extending alongside said container body tosaid seam, said peripheral portion and said domed portion beingdeformable under greater stress loads than said seam wall whereby uponoverpressurization said seam wall is caused to deform thereby openingsaid vent means.

6. A method of making a safety vent in a pressurized containercomprising the steps of providing a container having an outwardlydirected flange at one end, forming opening means in the flange,providing a distendable end closure, connecting the end closure to thebody by double seaming the flange to said end closure an extent to burythe opening means in the seam in a location whereat upon said endclosure becoming distended said seam will open and expose said openingmeans to evacuate the container.

7. In a container having an end member and a body member and a seaminterconnecting said members, openings, formed in one of said membersenclosed within said seam and openable attendant to the deflection ofsaid end member consequent to internal overpressurization of saidcontainer to provide means to evacuate the container.

8. A container as defined in claim 7 and a sealing compound in the seam,said compound being extruded through said openings and upon thedeflection of said end unit being blown out from said venting means toeffect subsequent release of the gases pressurizing said container.

9. The invention defined in claim 7 wherein said double seam is disposedin shielding relation to the venting means to direct the pressuredmaterial venting from the container in a predetermined pattern.

10. A safety venting system for a double seam structure of the typesecuring an end unit to a flanged container body, said container bodyincluding a body wall terminating at an outwardly directed body hookradius followed by a body hook, said end unit including a chuck wallmerging with a securing panel which in turn merges with a seaming wallwhich in turn merges with an end hook, said body hook being sandwichedbetween said seaming wall and said end hook, said venting systemcomprising a plurality of openings in said body hook radius, saidopenings normally being covered by said securing panel, said openingsbeing uncovered upon the deflection of said end unit consequent tointernal overpressurization thereby controllably venting the interior ofsaid container to the atmosphere.

11. In a safety venting system, a double seam structure of the typesecuring an end unit to a flanged container body, said container bodyincluding a body wall terminating at an outwardly directed body hookradius followed by a body hook, said end unit including a chuck wallmerging with a securing panel which in turn merges with a seaming wallwhich in turn merges with an end hook, said body hook being sandwichedbetween said seaming wall and said end hook, said venting systemcomprising a plurality of openings in said securing panel, said openingsnormally being covered by said body hook radius, said openings beinguncovered upon the deflection of said end unit consequent to internaloverpressurization thereby controllably venting the interior of saidcontainer to the atmosphere.

1. Safety venting means for a double seam structure of the type securingan end unit to a flanged container body, said venting means comprisingopenings buried in said double seam, said openings being uncoverableupon the deflection of said end unit consequent to internaloverpressurization of the container.
 2. Safety venting means for adouble seam structure of the type securing an end unit to a flangedcontainer body, said venting means comprising a plurality of openings inthe body of the container, said openings being buried in said doubleseam and being uncoverable upon the deflection of said end unitconsequent to internal overpressurization of the container.
 3. Theinvention according to claim 1 wherein said body comprises a radiallyoutwardly directed flange and said openings disposed at the juncture ofsaid flange and said body and being folded over into said seam. 4.Safety venting means for a double seam structure of the type securing anend unit to a flanged container body, wherein said body has a flange atsaid seam and said venting means comprises at least one opening in saidflange; said opening being buried in said double seam and beinguncoverable upon the deflection of said end unit consequent to internaloverpressurization of the container.
 5. The invention according to claim1 wherein said end unit comprises a central domed portion and aperipheral relatively rigid portion including a seaming panel extendingalongside said container body to said seam, said peripheral portion andsaid domed portion being deformable under greater stress loads than saidseam wall whereby upon overpressurization said seam wall is caused todeform thereby opening said vent means.
 6. A method of making a safetyvent in a pressurized container comprising the steps of providing acontainer having an outwardly directed flange at one end, formingopening means in the flange, providing a distendable end closure,connecting the end closure to the body by double seaming the flange tosaid end closure an extent to bury the opening means in the seam in alocation whereat upon said end closure becoming distended said seam willopen and expose said opening means to evacuate the container.
 7. In acontainer having an end member and a body member and a seaminterconnecting said members, openings, formed in one of said membersenclosed within said seam and openable attendant to the deflection ofsaid end member consequent to internal overpressurization of saidcontainer to provide means to evacuate the container.
 8. A container asdefined in claim 7 and a sealing compound in the seam, said compoundbeing extruded through said openings and upon the deflection of said endunit being blown out from said venting means to effect subsequentrelease of the gases pressurizing said container.
 9. The inventiondefined in claim 7 wherein said double seam is disposed in shieldingrelation to the venting means to direct the pressured material ventingfrom the container in a predetermined pattern.
 10. A safety ventingsystem for a double seam structure of the type securing an end unit to aflanged container body, said container body including a body wallterminating at an outwardly directed body hook radius followed by a bodyhook, said end unit Including a chuck wall merging with a securing panelwhich in turn merges with a seaming wall which in turn merges with anend hook, said body hook being sandwiched between said seaming wall andsaid end hook, said venting system comprising a plurality of openings insaid body hook radius, said openings normally being covered by saidsecuring panel, said openings being uncovered upon the deflection ofsaid end unit consequent to internal overpressurization therebycontrollably venting the interior of said container to the atmosphere.11. In a safety venting system, a double seam structure of the typesecuring an end unit to a flanged container body, said container bodyincluding a body wall terminating at an outwardly directed body hookradius followed by a body hook, said end unit including a chuck wallmerging with a securing panel which in turn merges with a seaming wallwhich in turn merges with an end hook, said body hook being sandwichedbetween said seaming wall and said end hook, said venting systemcomprising a plurality of openings in said securing panel, said openingsnormally being covered by said body hook radius, said openings beinguncovered upon the deflection of said end unit consequent to internaloverpressurization thereby controllably venting the interior of saidcontainer to the atmosphere.